Controlled collapse chip connection devices (flip chip) are known to have poor thermal paths to dissipate generated heat. To compensate for this, prior art heat sinking methods utilized metallic heat sinks placed in proximate locations to the flip chip via a thermal contact, such as a spring. Metallic heat sinks cannot be directly bonded to a flip chip because the metallic heat sinks have a high thermal expansion coefficient in comparison to the thermal expansion coefficient of the flip chip. If a metallic heat sink is directly bonded to a flip chip, undue stress is put on the flip chip as each part expands and contracts with heating and cooling. This stress can cause damage to the flip chip and render it inoperable.
One method to obtain physical contact between a metallic heat sink and a flip chip uses a thermal compound composed of a slippery material with thermally conducting particles. However, this method is not as thermally conductive as desirable because the thermal compound is typically 10 to 20 times less thermally conductive than solder.
Therefore, a need exists for a method of heat sinking a flip chip that eliminates undue stress on the flip chip due to different expansion coefficients and provides direct thermal coupling between a heat sink and the flip chip.